The invention relates to an oil filler for an internal combustion engine. These oil fillers are usually provided in or adjacent a valve cover and comprise an oil filler opening which is closed with a cap.
It is generally known to provide pressure control valves for crankcase ventilation, for example in the vent line between the crankcase and the air intake filter or intake manifold. With these pressure control valves there is a continuous connection between the crankcase and the air intake side of the engine through which so-called blow-by gases are aspirated and returned to the combustion process. The pressure control valve assures that the vacuum in the crankcase does not fall below a certain level. A constantly prevailing light vacuum in the crankcase prevents blow-by gases from escaping into the free atmosphere. By controlling the crankcase pressure, the internal combustion engine system is assured of maximum containment so that no pollutants can pass into the free atmosphere.
A pressure control valve of this kind is usually flange-mounted to the side of the engine and is connected by appropriate connecting lines to the crankcase and intake manifold or air filter. Such valves are disclosed, for example, in publication No. VKD 7032 of Filterwerk Mann & Hummel GmbH. The pressure control valve is usually fastened to the engine body with a flange or a steel bracket.
For the sake of the appearance of the engine compartment, it is necessary to design such engine-mounted components accordingly, and provide them, for example, with covers or the like. This, however, calls for considerable effort and consequently involves additional expense.
Mueller et al, Published German Patent Application No. DE 4,017,074 discloses a pressure control valve which is arranged in a combination unit with oil filler tube and oil dip stick. This pressure control valve, however, is still connected to the intake manifold or air intake tube of the engine, so that it is difficult to inspect and/or replace the valve.